Synthetic high density lipoproteins (sHDL) are discoidal lipoprotein particles made of an apolipoprotein and a phospholipid, which mimic most, if not all, of the atheroprotective properties of plasma HDL, including stimulation of reverse cholesterol transport (RCT), prevention of endothelial dysfunction, and inhibition of lipid oxidation. sHDL are currently under development as a novel treatment for atherosclerotic cardiovascular disease. A number of preclinical studies have demonstrated the ability of single or multiple injections of sHDL to induce the regression of atherosclerotic plaques and prevent arterial restenosis. In the first phase II trial in patients with acute coronary syndromes, a short-term treatment with sHDL containing the disulfide-linked dimer of the apolipoprotein A-IMilano variant (A-IM/A-IM) caused a remarkable reduction of atheroma volume. sHDL also display a direct cardioprotective activity in ex vivo and in vivo models of myocardial ischemia/reperfusion (I/R) injury, and may become a useful adjunctive therapy to improve clinical outcomes in patients with acute coronary syndromes or undergoing coronary procedures.